Air compensator for gas burners



Feb. 23, 1954 TH N 2,670,034

AIR COMPENSATOR FOR GAS BURNERS Filed Aug. 2, 1951 2 Sheets-Sheet l ENTOR. 5 Ha /y 5 7770/77 50/? Feb. 23, 1954 E, THOMPSON 2,670,034

AIR COMPENSATOR FOR GAS BURNERS Filed Aug. 2, 1951 2 SheetsSheet 2 INVENTOR. My 5 7770/7000 ATTORNEY Patented Feb. 23, 1954 UNITED STATES PATENT 2,670,034 OFFICE AIR COMPENSATOR FOR GAS BUBNERS Harry E. Thompson, Steubenville, Ohio Application August 2, 1951, Serial No. 239,897

13 Claims.

This invention relates generally to the class of gaseous fuel burners and is directed particularly to improvements in air supply control means.

The present invention comprises what might be termed an air compensator and has for its principal obiect to provide a means for more effectively controlling the flow of air to th air inlet ports which are found at the outer end of the venturi through which passes the air and gas mixture to a burner head, whereby the air stream moves to the inlets without fluctuation and there is avoided, as a result. the back firing which often occurs in the venturi of the burner structure.

.Another object of the invention is to provide an air control means for attachment to a burner unit of the character stated, which is designed so that it can be installed without materially changing the burner unit.

Still another object of the invention is to provide an air control means of the character stated with a modified burner fitting by which the control means supported at one end for adjustment.

Still another obieet of th invention is to provide an air control means of the character stated which replaces the present air shutter and which, by adjustment upon the burner fitting, regulates the amount of air permitted to enter the burner venturi for mixture with the gas flowing from the fitting into the venturi.

Other objects and advantages of the invention will become apparent as the description of the same proceeds and the invention will be best understood from a consideration of the following detailed description taken in connection with the accompanying drawings forming a part of the specification, with the understanding, however, that the invention is not to be limited to the exact details of construction shown and described since obvious modifications will occur to a person skilled in the art.

the drawin s:

Figure 1 illustrates a portion of a typical circulator burner such as is employed in gaseous fuel heaters, showing thereon, partly in elevation and partly in section an air compensator r regulator constructed in accordance with one embodiment or the present invention in association with a modified burner fitting.

Figure 2 is a sectional view taken substantially on the line 2-2 of Figure 1.

Figure 3 is a sectional view taken substantially on the line 3- .3 of Fi ure 1.

Figure is a view in side elevation of a second embodiment of the air regulating device.

Figure 5 is a transverse section taken substantially on the line 55 of Figure 4.

Figure 6 illustrates a modified'head or outer end construction.

Figure '7 illustrates-another modified head or outer and construction.

Figure 8 is a view in side elevation .of another embodiment .of the invention.

Figure 9 is a transverse section taken substantially 01 the line lie-9 of Figure 8.

Figure 10 is a view in elevation of the outer or front end of the embodiment illustrated in Figure 8.

Figure 11 is a detail illustrating another form of connection between the burner fitting and the vend wall of a regulator.

Referring now more particularly to the drawi gs the numeral ID designates in Figure l, a portion of the head of a circulator burner while the numeral l2 generally desi nates the usual long air and gas mixture conducting Venturi tube which leads to the burner head Hi and which has at its free outer end the wall M in which are formed air admission openings l6 and a central opening l8.

In conventional burners the wall M at the outer end of the venturi I2 is eouipped with an air shutter, not shown, which regulates t e flow of air through the openings I6. For the purposes of the present invention such air shutter is done away with.

The burner fitting 20 here illustrated is of the adjustable orifice type but since such a type of fitting which is coupled with the ga mani old 22. In this modified fitting the stem or nozzle 24 is of greater length than in the conventional fitting and in one embodiment of the invention is provided with the screw threads 25 for the purpose hereinafter described. This stem or nozzle 24 is of a diameter to fit fairly snugly in the central opening I8 of the Venturi wall M, as illustrated.

The burner fitting 20 here illustrated is of adjustable orifice type but since such a type of fitting is standard form and well known it is not believed necessary to give any detailed description or illustration of the same. It could also be a solid end type of fitting or non-adiustable.

In accordance with the present invention in one embodiment thereof there is provided the relatively long metal air housin in the form of a cylinder 26 which is closed at one end, hereinafter termed the forward or outer end, by the wall 21, in the center of which is an internally threaded forwardly projecting collar 28 defining the central opening 29. In this opening is threadably fitted, when the devic is installed, the burner fitting stem '24 as illustrated in Figure l.

The inside diameter of the cylinder 26 is slightly greater than the overall diameter of the forward end of the venturi l2.

The air cylinder or housing is installed over the venturi in the nature of a sleeve as shown and the inner end of the cylinder which is open, has sliolably fitted therein the spider 3,0 which comprises the inner collar 31 which is fitted around the venturi, the radial arms or spokes 32 and the outer rim 33 which is carried by the spokes and which .fits ins de he en end o the cy nder :26-

.dnr s it bl means ma be employed for m ntof the venturi for movement into the latter through the apertures it, when the forward wall 2i of the cylinder is properly spaced from the wall it of the venturi. Such apertures need not be restricted any longer as to shape or size in this burner design. The entire face of venturi except for valve supporting member may be open,

providing for maximum air opening as required and ease of casting in foundry.

To facilitate the maintenance of the walls 2i and M in the proper relation, the wall 27! is provided with at least two tapped openings 36in each of which is threaded a lock screw 3! which, after the housing or cylinder 26 has been properly adjusted, are threaded inwardly for abutment against the Venturi wall i i so as to hold the cylinder in set position.

The adjustment of the spacing between the walls i l and 2? is accomplished by rotating the cylinder 25 so that it will, be threaded inwardly or outwardly on the stem 2& and to facilitate such rotation the cylinder at its outer end is provided with a suitably roughened or knurled surface as indicated at 38.

In the embodiment of the invention as illustrated in Figure 1 the cylinder or housing has been shown as formed in one piece as a drawn or cast tube. The material for this and the other embodiments may be steel, brass, aluminum or any suitable alloy.

In Figures 4 and there is illustrated a second form or embodiment of the housing or cylinder. In this embodiment the cylinder is generally designated a and is of two-part construction in that it comprises the body portion which may be of one piece, either seamed or seamless, and a drawn cap it which is fitted over theouter or forward end of the body and spot welded or otherwise permanently fixed thereon as indicated at 59. This cap has its periphery knurled as at M for the purpose above set forth and it is provided with the central threaded collar l2 for receiving the threaded stem of the burner fitting and with tapped openings it for the lock screws 3i.

In this modified embodiment shown in Figures 4 and 5, the inner end of the cylinder has fitted therein the annular baffle wall id the central opening d5 of which receives the body of the venturi i2. This baffle wall is provided with a number of air inlet openings at.

As in the case of the spider 3d, the baflie and spider plate M is for the purpose of centering the tube on the burner venturi, the bafiie providing a means whereby the air supplied to the burner mixer can be controlled. This design provides a fixed air supply for one style of burner in most cases. The compensator, accordingly, being designed for the individual burner and the air openings in the baffle plate t l, being of a size, number and shape to suit the air requirements.

The spider and air bafiie arrangement may, therefore, vary to suit one or many burners in accordance with the design required for the burner size. Any suitable means may be used for securing the spider bailie id on the burner mixer or Venturi tube.

In Figures 6 and 7 two other arrangements are illustrated for efiecting the assembly of the two parts of the device which, is shown in Figure 4 as having the body and head or cap spot welded together. In the arrangement shown in Figure 6 the cylinder 26b is shown as having its forward end screw threaded asindicated at 7 and the cap which is designated ila is also screw threaded internally for threaded engagement on the end of the cylinder.

In the modification shown in Figure 7 the cylindelwhich is designated 250 is provided with a pair of radially directed pins All on the outer wall thereof diametrally opposite pointaone only of such pins being shown, and the head or cap ti'o slips over the forward end of the cylinder body and is provided with a bayonet slot it for each of the pins or lugs ill. Thus the cap is efiectiveiyloclzed position by the bayonet slot coupling illustrated.

Figures 8 to 10 illustrate another embodiment of the invention wherein use is made of a number of bafiles inside the cylindrical housing and surrounding the Venturi tube. In this third emb'. 'nent the cylinder or housing is generally nated 28d and is initially formed in the two longitudinal sections a each of which has a semicircular end wall "0 and the sections are bordered along the longitu a1 edges and the edges of the end walls by the lateral flanges 58. These flanges are placed together and secured by welding or in any other suitable manner. At the outer end of the cylinder the flanges which extend across the end wall portions b are shaped to provide the fitting stern receiving collar 5i and each wall portion i also provided with a tapped opening 52 to receive a lock screw.

In this embodiment the collar 5! may be internally threaded like the collars 23 and Q2 or it may be smooth as illustrated to snugly receive a fitting stem which is also smooth or unthreaded such as the stem indicated at 53 in Figure 11. When a smooth collar and stem are employed the collar is provided with a suitable set screw 5i whi .1 is adapted to have locking engagement with the fitting stem to hold the cylinder against axial movement. It will be readily apparent from the foregoing that instead of rotating the cylinder to make the desired adjustment the cylinder is merely slipped inwardly or outwardly on the smooth stem and when the desired adjustment obtained the set screw 54 is threaded inwardly into contact with the stem 53.

In the event that the collar 5i is provided with screw threads so that rotation of the cylinder is required to make the desired adjustment, the flanges extending across the forward or outer end of the cylinder provide a convenient finger hold means for effecting the turning of the cylinder.

In the embodiment of Figures 8 to lOthe cylinder is provided with a number of longitudinally spaced internal bafiles in the form of annular flanges which have alternately large and small openings.

At the inner end of the cylinder another type of spider design illustrated which functions as a baiiie and; also to center the air compensator or cylinder body on the Venturi tube. This com- 'binedspider and baffle is designated 55 andthe central opening 5'5 thereof is of a diameter to fit snugly around the Venturi tube so as to maintain the cylinder concentric with the tube.

For the admission of air into the cylinder past the baffle spider structure 56, such bafile is provided with a number of openings 58 as illustrated in Figure 9.

The baffle arrangement shown in Figure 8 provides an effective flow of air control, speed and volume of air to obtain the accuracy required for pre-mixing and control of air flow to the air admission openings [6 in the wall at the forward end of the Venturi tube.

As previously stated where the cylinder or housing collar and burner fitting stem are machined to fit snugly together the desired accurate adjustment of the cylinder can be made by sliding the same back and forth on the fitting stem to bring the forward wall of the cylinder body and the apertured wall M of the Venturi into the desired spaced relation for the admission of the proper amount of air to the Venturi.

In each of the several embodiments of the invention the baffles also function to secure quietness of burner operation.

In connection with the previously referred to back-firing which the present invention prevents, this is also called noise of extinction, and may be due to burner design, but it is also due to the creation of alean, or explosive, air gas mixture which forms immediately after the gas is shut 01?. Such a lean mixture is practically eliminated by the present invention, giving as a result, a quiet shut-off.

The invention is particularly useful where manufactured gas is used, where burner designers have great difficulty in obtaining quietness of extinction. It is also very satisfactory on LP-gases, which are difhcult in this respect as well.

I claim:

1. In a gaseous fuel burner including an air and gas conducting Venturi tube having an end wall provided with a central opening and air admission openings and having its opposite end connected to a burner, a gas inlet nozzle having a stem portion extending into said central opening, a cylinder housing encasing a major portion of said tube and having an outer end wall, said cylinder housing end wall being opposed to and spaced from said Venturi end wall, said cylinder housing end wall having an opening through which said nozzle stem extends and in which the stem is engaged, and means within the inner end of the cylinder housing and bearing against the tube to center the cylinder housing on the tube, the inside diameter of the cylinder housing being greater than the maximum diameter of the Ven turi tube to provide space for the passage of air through the cylinder housing and tube and between said tube and housing end walls to said air admission openings, and said cylinder housing being open at the inner end for the admission of air thereinto.

2. The invention as set forth in claim 1, wherein the cylinder housing is adjustable axially on said nozzle stem, and means for locking the Venturi tube and cylinder housing together, said means being operatively associated with the Venturi tube and cylinder housing.

3. The invention as set forth in claim 1, wherein the cylinder housing end wall central opening is threaded and said stem is threaded for engagement with wall opening threads.

4. The invention as set forth in claim 1, wherein the cylinder housing end wall central opening and the nozzle stem are machined to a smooth sliding fit for the axial sliding adjustment of the cylinder housing on the stem, and means for securing the cylinder housing against axial movement.

5. The invention as set forth in claim 1, with an air baille within the cylinder housing and encircling the Venturi tube.

6. The invention as set forth in claim 1, wherein the cylinder housing and end wall are comprised in a single piece of metal.

'7. The invention as set forth in claim 1, wherein the said end wall comprises a cap piece secured on one end of the cylinder housing.

8. The invention as set forth in claim 1, where in the said means comprises a spider encircling the Venturi tube.

9. The invention according to claim 8, wherein the spider also comprises an air bailie.

10. The invention according to claim 8, in which the spider is in the form of an annular plate providing a battle with air openings therein.

11. The invention according to claim 8, and a plurality of annular baffle plates in and secured to the wall of the cylinder housing in spaced relation longitudinally thereof and encircling and spaced from the Venturi tube.

12. In a gaseous fuel burner including an air and gas conducting Venturi tube having an outer end wall provided with a central opening and air admission openings and having its inner end connected with a burner, a gas inlet nozzle having a stem portion extending into said central opening, a cylinder housing having a wall across one end, the housing encasing said tube and the outer end wall thereof, said cylinder housing end wall having a central opening thru which said stem portion extends and. by which the cylinder housing is supported on the stem portion, the inside diameter of the cylinder housing being greater than the maximum diameter of the Venturi tube and said cylinder housing end wall being spaced from the Venturi tube end wall, whereby air passes through the housing and between the Venturi tube and housing end walls to said admission openings, the other end of said cylinder housing being open for the admission of air thereinto, means within the cylinder housing connected between the same and the Venturi tube for centering the cylinder housing on the tube, and means carried by the cylinder housing for engagement with the tube end wall for holding the cylinder housing in set position.

13. The invention according to claim 12 wherein said means for holding the cylinder housing in set position comprises a screw member threaded through a threaded opening in the cylinder housing end wall and extending across the space between said end wall and bearing against the Venturi tube end wall.

HARRY E. THOMPSON.

References Cited in the file of this patent UNITED STATES PATENTS Number Name Date 398,505 Gibbons Feb. 26, 1889 781,454 Palmer 1 Jan. 31, 1905 836,114 Hulse Nov. 20, 1906 1,731,306 Hileman Oct. 15, 1929 2,360,310 Anderson Oct. 17, 1944 FOREIGN PATENTS Number Country Date 13,243 Great Britain of 1894 4,126 Great Britain of 1915 

